The present invention relates to a print head for printing optical structures on a substrate comprising an ejection device for ejecting at least one droplet of a printing ink towards the substrate and a curing device for curing the at least one deposited droplet.
It is common knowledge that products provided with optical structures can be manufactured in a comparably time-saving and inexpensive way by printing the optical structures directly on an appropriate substrate. Suchlike imprinted optical structures comprise lenses, mirrors or retroreflectors, for instance. The substrate can be made of synthetic material or glass. Furthermore, it is well known to cure the imprinted material by using light irradiation for reducing the overall printing time.
For Example, German patent application DE 10 2006 003.310 A1 discloses a method for producing optical lenses from a moldable transparent material comprises a first step of depositing the material on a substrate in a layer that is cured by a laser or by UV irradiation in a subsequent second step.
The drawback of such an approach is that a mercury-vapor lamp, usually used as UV source, or a laser are very expensive and that it is very difficult to implement suchlike light source into a compact and movable print head.
In particular, an integration of suchlike print heads in conventional inkjet printers in order to easily upgrade a conventional inkjet printer for printing optical structures at reasonable prices is not feasible.